The present invention relates to clamps for mounting tubes obliquely onto surfaces where the surface and the tube may be undergoing relative vibration, and particularly, to clamps for mounting tubes to components of a vehicle motor.
A modern automobile motor requires or is provided with a variety of accessory apparatus which involve the use of tubes to transmit pressurized fluid (such as exhaust) or provide a vacuum, to a portion of the motor block, carburetor, intake or exhaust manifolds, or other component. For example, an EGR (exhaust gas recirculation) tube directs hot exhaust gases from the exhaust manifold or other part of the exhaust system, to the carburetor or air intake manifold, which improves fuel efficiency and, as well, improves the quality of the vehicle's exhaust emissions.
Typically, the tube will be insertingly received at its ends directly into apertures provided in the sidewalls of the respective motor components. Each end of the tube may be provided with a outwardly extending, annular bead, to, in part, limit the extent to which the tube extends into the sidewall of the motor component, and as well to provide a surface for the clamp to bear on, to hold the tube end in place.
A typical prior art clamp used to secure a tube end would be fabricated as a simple plate-like retainer member, with a first bolt aperture in a clamp attachment region for attaching the retainer member to the sidewall. Another, second tube aperture would be provided in an opposite end of the retainer member, in tube retaining region, to receive the tube end. The diameter of the tube aperture would be large enough to receive the tube end, without binding. On the surface of the retainer member facing the sidewall, around the tube aperture, an inwardly angled chamfer would partially accommodate the bead, but the chamfer would not be so deep as to completely surround the bead. Were the bead to be completely surrounded, the tube retaining region of the retainer member would lie flat on the sidewall, taking substantially all of the pressure off of the bead, reducing the sealing force of the clamp. Instead, the chamfer only partially receives the bead, and the clamp, when installed, fits flush to the sidewall at the clamp attachment region, and is separated from the sidewall, at the tube retaining region, a short distance by the bead.
The tube end is, naturally, subjected to substantial vibration, in the environment of a vehicle motor, particularly in a mounting on or in the vicinity of the motor block. Such tubes as the EGR tube, are constructed with thin walls, to conserve weight and enhance flexibility. Vibrations, such as transverse vibrations, are felt by the tube end primarily in the areas surrounding the bead, which itself is held immobile by the clamp. Accordingly, failure of the tube end around the bead is accelerated by the vibrations of the tube away from the bead.
A possible solution, which has been considered, is to merely reduce the clearance between the inside of the tube aperture and the tube. However, due to the thin-walled nature of the tube, any slight misalignment of the tube with respect to the clamp and the aperture in the sidewall, would cause the edge of the inside of the tube aperture to bear excessively against the tube, leading to the buckling and failure of the tube. It is often desirable to permit the EGR tube, or other such tube, to be installed at a slight misalignment, to help accommodate the variations in dimensions and tolerance build-ups which may exist from vehicle to vehicle.
The provision of vibration-absorbing or dampening elastomeric elements would likewise not be an acceptable solution, as the EGR tube, and other such tubes, carry high temperature fluids or are otherwise in high temperature environments. Elastomeric materials typically cannot function, or remain solid and stable, at such temperatures over prolonged periods of time. Such elastomeric materials likewise typically do not perform well in extreme cold, in that the flexibility and resiliency of the material is reduced or eliminated.
It is an object of this invention, therefore, to provide a clamp apparatus for mounting a tube end to a sidewall of a motor or motor component, which clamp apparatus is configured to lengthen the useful lifespan of the tube by reducing the magnitude of the harmful transverse vibrations which the tube end undergoes.
It is another object of the invention to provide a clamp apparatus which is capable of effectively clamping a tube with the tube end in slight misalignment relative to the clamp apparatus or the sidewall, without potentially damaging the tube.
A further object of the invention is to provide such a clamp apparatus which is capable of functioning in extreme temperature environments.
These and other objects of the invention will become apparent in view of the present specification, claims and drawings.